A coaxially connected structure for opposed wiring substrates of the present invention includes a first substrate equipped with a tab type bracket and a second substrate equipped with a socket type bracket, and further includes first and second ground cases respectively mounted on the first and second substrates to cover them. The first and second ground cases are respectively provided with first and second penetration openings to pass the tab type bracket and the socket type bracket therethrough. Exposed parts of the tab type bracket and the socket type bracket from the openings are mutually engaged and being fully surrounded with at least one conductive tubular member which has a function to determine a distance between the first substrate and the second substrate.